New webapp Guestmob promises that their algorithms and carefully curated relationships with hotels in its markets will save you a good deal of money when you book your next vacation. Looking at the prices the service offers, they can definitely deliver on their promised discounts—the catch is you have to be willing to give up a little control about where you stay to get the best price.

Guestmob is available in about 20 major US markets, including cities like New York City, Washington DC, Dallas, Los Angeles, Seattle, and more. Each city is broken up into regions, and once you're registered and logged in (you can sign up with Facebook or create an account via email) you can select your destination and the dates of your visit. You'll see the regions of the city, the hotels in that area, and the average room prices for each location. Select the region you'd like to stay in, and you'll get more information about the specific hotels in each area, and you'll be able to see how much Guestmob can save you over already-published booking prices at other travel sites.

When I tested it, Guestmob was able to save me about 15% off over the lowest available rates for all four hotels in the New York area I searched for the same dates. Here's the catch: when you book, you book a region, and you don't know which hotel you're staying in until Guestmob finishes the negotiations for you. This only matters if you're worried about one of the hotels in a region, and from what I could see, all of the hotels in every region I browsed were all well rated. Even so, you have to be willing to give up that control to get the additional bargain. If you land a hotel you hate, your booking is fully refundable, and you can try again.

Hotel prices being what they are, there's definitely room for a service like Guestmob, but the lack of precise control might turn some people off. What do you think? Would you be willing to give it a shot if it saved you money, or are you uncomfortable letting go of the reins? Share your thoughts in the comments.